Lunitidal interval Definition
It is the mean time interval between the transit of the moon over the local meridian and the next high or low tide. Tides are periodic rises as well as falls of ocean water that are caused by the gravitational interaction between the Earth and the Moon.
It generally gives the time difference between two natural events that occurs simultaneously. The first event is when the moon passes over a meridian. The second event happens when the corresponding water tide reaches its highest peak. Practically, these two events do not take place simultaneously due to certain geographical features and disturbances. This in turn causes a time lag or interval between the transit of the moon and when the tide attains the highest level. It is also known as high water interval (HWI).